Drill



A. FISCHER March 12, 1968 DRILL Filed June 14, 1966 INVENTOR.

ARTUR FISLHER BY 7 a d r v'lmr- United States Patent 3,372,763 DRILL Artur Fischer, 133 Grunmettstetterstn, 724'1 'Ihmlingen, Germany Filed June 14, 1966, Ser. No. 558,211 Claims priority, application Germany, June 14, 1965, F 46,325 10 Claims. (Cl. 175-323) The present invention relates to a drill. More specifically, the invention relates to a drill having means for facilitating escape of comminuted material from a bore hole produced by such drill.

It is known to provide drills, particularly drills for use in making bore holes in masonry walls and ceilings, with grooves extending along the shank of the drill for the purpose of facilitating the escape of comminuted material from the bore hole. However, the provision of such grooves is the drills, which are made from very hard steels, is relatively complicated and expensive. Furthermore, friction of the material during massage along these grooves makes the escape of material less easy than is desirable.

It is therefore a general object of the present invention to provide a drill which does not have the abovementioned disadvantages of the prior art.

A more specific object of the invention is to provide a drill having means for facilitating escape of comminuted material from a bore hole made with the drill and being simple and inexpensive to construct.

A concomitant object of the invention is to provide such a drill in which the friction of material escaping from a bore hole made with a drill is significantly reduced over what is known from the prior art.

In accordance with one feature of my invention I provide a drill comprising a shank having a front end portion and a rear end portion. This shank carries a drill bit on its front end portion. Furthermore, I provide an elongated jacket of synthetic plastic material which extends between the front end portion and the rear end portion and has an external face provided with at least one groove extending over the entire length of the jacket. Thus, comminuted material resulting from drilling of a bore hole with the drill is enabled to escape from the bore hole along the groove. Naturally, it will be understood that the use of a plastic material greatly reduces friction of the comminuted material during its passage through the groove, and at the same time the use of such plastic material in the form of a jacket makes the construction of the novel drill much simpler and much less expensive.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, to-

gether with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is an elevational view of a novel drill in accordance with the present invention, with the plastic jacket partially broken away;

FIG. 2 is a view taken in the direction of the arrow A of FIG. 1;

FIG. 3 is a perspective view of a drill bit finding use with the drill of FIG. 1;

FIG. 4 is an elevational view, partly in section, of another embodiment of the invention;

FIG. 5 is a view of the embodiment in FIG. 4, as seen in the direction of the arrow B thereof;

3,372,763 Patentedl Mar. 12, 1968 FIG. 6 is a section taken through the embodiment shown in FIG. 4 0n the line VI-VI thereof; and

FIG. 7 is a view showing the novel drill according to the present invention in use for drilling a bore hole in masonry.

Discussing now the drawing in detail, and firstly FIG. 1 thereof, it will be seen that the drill is generally indicated with reference numeral 1. It comprises a shank 1a and a front end portion 1b and the shank is surrounded by a plastic jacket 2. This jacket 2 of synthetic plastic material may be constructed as a separate member to be placed onto the shank 1a, or it may be directly applied thereonto by a spraying or injecting process. The front end portion 1b of shank 1a is flattened so as to have a polygonal, in the present embodiment rectangular, cross section, as is most readily evident from FIG. 2. Since this front end portion 112 is partially surounded by the plastic jacket 2 a rotation of the latter with respect: to the shank 1a is thus precluded. The plastic jacket 2 is provided in its external face with at least one groove, preferably of helical configuration, which is indicated in FIG. 1 with the reference numeral 2a. As is evident from FIG. 7, comminuted material can pass along this groove from the interior of a bore hole which has been drilled with the novel drill and is thus evacuated from the bore hole. A tough synthetic plastic material, such as nylon or Teflon, having a low coefiicient of friction, is particularly suited for constructing the jacket 2.

As seen in FIG. 3 I provide separately a drill bit 3 having a recess 3a which corresponds to the cross sectional configuration of the front end portion 1b of shank 1a. It will be clear that the front end portion 1b is to be received in the recess So so that the drill bit 3 is nonrotatably joined to the drill 1. It will now be further obvious from what has just been said that, after the drill shown in FIGS. 1-3 has been used for drilling a bore hole in masonry material, such as is illustrated in FIG. 7, the shank 1a is withdrawn from the bore hole and the drill bit 3 remains therein. Thus, the shank 1a, including its plastic jacket 2, can be simply reused by joining a new drill bit 3 thereto.

A second possible embodiment of the present invention is shown in FIGS. 4-6. It corresponds substantially to the embodiment shown in FIGS. 1-3. The plastic jacket in this second embodiment is generally indicated with reference numeral 12 and it will be noticed that it is in the form of a separate sleeve-like member provided with a center passage 120 of substantially circular cross section. The internal face of this jacket is provided over its entire length with axially extending grooves 12d which receive, when the jacket is slipped onto the shank 11a of the drill 11, projections or keys provided on the shank 11a. Thus, the plastic jacket 12 is secured against rotation with respect to the shank 11a. The drill bit 13 corresponds substantially to the drill bit 3 shown in FIG. 3 and recives in its recess the front end portion 11b of the shank 11a. Unlike the embodiment in FIGS. 1-3, however, the drill bit in FIGS. 4-6 is non-releasably secured to the front end position 11b of the drill 11. Thus, the drill in its entirety, including the drill bit 13, is withdrawn when a bore hole has been completed and the entire drill can be re-used. This is not to say, of course, that the drill bit 13 could not be provided as a separate and releasable member in the manner of the drill bit of FIG. 3, if such should be desired. The advantage of providing a separate and releasable synthetic plastic jacket 12, as seen in the embodiment of FIGS. 4-6, lies in the fact that the jacket can be readily removed and replaced with a new one if damage to it should occur.

Although it has been found that in either of the embodiments various different types of grooves can be advantageously used in the respective plastic jackets, it is preferred to use a helical groove of relatively broad cross section and relatively slow pitch. FIG. 7, in which a novel drill in accordance with the embodiment of FIGS. l3 is shown gripped by the chuck 7 of a drilling tool 3 for drilling a bore hole into a masonry structure 6, shows how the groove in the outer face of the plastic jacket 2 evacuates cornminuted materal 4 from the bore hole 5. ests have shown that the evacuation of such comminuted material by a novel drill in accordance with the present invention is considerably improved over conventional drills known from the prior art.

Furthermore, it has been found that the provision of the jacket of synthetic plastic material considerably decreases the danger of breakage of the drill shank, particularly in case of shanks of small diameter, if the drill should become jammed in some fashion in the bore hole in the masonry structure. The reason for this is the fact that the plastic material is relatively resilient and thus cushions the metallic shank.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of drills differing from the types described above.

While the invention has been illustrated and described as embodied in a drill, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A drill, comprising a shank having a front end portion and a rear end portion; a drill bit carried by said front end portion; and an elongated jacket of synthetic plastic material extending between said front end portion and said rear end portion, said jacket having an external face provided with at least one groove extending over the entire length of said jacket so that comminuted material resulting from drilling of a bore hole with said drill can escape from such bore hole along said groove.

2. A drill as defined in claim 1, wherein said shank is of metallic material.

3. A drill as defined in claim 1, wherein said groove is of helical configuration.

4*. A drill as defined in claim 1, wherein said groove is of helical configuration and of slow pitch.

5. A drill as defined in claim 1, wherein said jacket is non-rotatable with reference to said shank.

6. A drill as defined in claim 1, and comprising means provided on said shank for preventing rotation of said jacket with reference to said shank.

7. A drill as defined in claim 1, wherein said jacket is removable from said shank.

A drill as defined in claim 1, wherein said drill bit is releasably carried by said front end portion.

9. A drill as defined in claim 1, wherein said drill bit is rigidly secured to said front end portion.

14 A drill as defined in claim 1, wherein said jacket consists of a synthetic plastic material selected from the group comprising nylon and Teflon.

References Cited UNITED STATES PATENTS 1,331,458 2/1920 Hoffman et a1 -394 1,616,666 2/1927 Nebergall 175323 2,714,500 8/1955 Snyder 175323 2,754,160 7/1956 Owen 175-323 X 2,773,672 12/1956 Holmes 175-394 X 2,856,157 10/1958 Chapin 175-323 X 2,902,260 9/1959 Tilden 175394 CHARLES E. OCONNELL, Primary Examiner.

NILE C. BYERS, JR., Examiner. 

1. A DRILL, COMPRISING A SHANK HAVING A FRONT END PORTION AND A REAR END PORTION; A DRILL BIT CARRIED BY SAID FRONT END PORTION; AND AN ELONGATED JACKET OF SYNTHETIC PLASTIC MATERIAL EXTENDING BETWEEN SAID FRONT END PORTION AND SAID REAR END PORTION, SAID JACKET HAVING AN EXTERNAL FACE PROVIDED WITH A LEAST ONE GROOVE EXTENDING OVER THE ENTIRE LENGTH OF SAID JACKET SO THAT COMMINUTED MATERIAL RESULTING FROM DRILLING OF A BORE HOLE WITH SAID DRILL CAN ESCAPE FROM SUCH BORE HOLE ALONG SAID GROOVE. 